1. Field of Invention
The subject invention is generally related to a device for determining the water depth of fishing lures and the like and is specifically directed to an on-line indicator for monitoring the depth of fishing bait as it is pulled through the water, the on-line indicator specifically including a sealed on/off switch and an encapsulated electronic unit.
2. Description of the Prior Art
With the development of electronic devices for determining water depth and determining the location of objects in the water, numerous electronic systems have been developed to aid fishing enthusiasts in locating and catching fish. For example, "fish finders" are well known and are used to determine the location of schools of fish in a body of water. The most sophisticated fish finders not only indicate the school but indicate the depth of the school within the specific location. It is common to troll crankbaits, lures and other baits through the water in the vicinity of the school in an effort to attract the fish toward the bait and draw a strike. Typically, this is accomplished by paying out a specific amount of fishing line from a rod and reel located within the boat and then trolling the boat across the surface of the water in the vicinity of the school at a specific speed.
It is common knowledge that different types of bait, dependent on configuration, weight, hydrodynamics and other factors will troll through the water at different, predictable depths. The depth of the bait being pulled through the water is also dependent upon the amount of line payed out from the rod and the speed at which the boat is trolling through the water. It is desirable to know with certainty at what depths specific baits will troll through the water under predefined conditions. For example, if a school of fish is found to be eight feet below the surface of the trolling boat, it is advantageous to know what bait can be secured to the line to troll the water in the vicinity of eight feet, greatly increasing the chances for drawing fish toward the bait. In a typical example, if 200 feet of line is payed out from the boat and the boat is trolling through the water at three miles per hour, specific baits will troll through the water at a predetermined and predictable depth. If the length of line or the speed is changed, the bait will react in a different manner. In the past, the depth of the bait has been determined through trial and error and, at best, the results have been less than accurate. However, detailed logbooks have been created cataloguing various baits under controlled conditions. Tournament participants, in particular, have relied on these logbooks in an effort to use bait consistent with the conditions in an effort to obtain predictable results. Such efforts have met with spotty success.
The aforementioned application, U.S. Ser. No. 08/137,894, now U.S. Pat. No. 5,351,538 is specifically directed to an on-line fishing depth indicator for determining the performance of a bait pulled through the water under specific, predetermined conditions. The fishing depth indicator of that invention has a hydrodynamic design permitting it to be pulled through the water with the bait without interfering with the performance of the bait, giving an accurate reading of the performance of the bait as it is trolled through the water. The preferred embodiment of that invention permits the indicator to be pulled through the water either in series with or in parallel with the subject bait without impairing the depth performance of the bait. The depth indicator may be secured in advance of the bait or in a trailing position behind the bait while still giving an accurate readout. As there shown, a visual readout is provided for indicating the maximum depth the bait has reached during the trolling operation. Preferably, the indicator includes a transparent window through which an LCD readout may be read for visually ascertaining the performance of the bait. In the preferred form, the depth may be read in either the English or the metric system.
Other examples of depth indicators for use in sport fishing, tournament fishing and the like are shown, for example, in U.S. Pat. No. 2,821,805 issued to W. Kunze on Feb. 4, 1958, and U.S. Pat. No. 3,038,143 issued to W. Dow on Jun. 5, 1962. The Kunze patent discloses a fish finding apparatus having a depth gauge attached to a net and adapted for pulling the net through the water at a specific depth in order to increase the chances that the net will be pulled through a school of fish. The Dow patent discloses a telemetering depth meter and a hydrophone adapted for pulling a net through the water at a specific depth. Both the Kunze and Dow patents are particularly suited for commercial fishing. Neither of these devices is readily capable for sport fishing and is not adaptable for determining the operating depth of specific baits.
Examples of depth sensitive transducers are shown in U.S. Pat. No. 3,308,425 issued to McLoad on Mar. 7, 1967, U.S. Pat. No. 4,225,952 issued to Lewis on Sep. 30, 1980, U.S. Pat. No. 4,926,397 issued to Robertson on May 15, 1990 and U.S. Pat. No. 4,943,951 issued to Leayell, et al on Jul. 24, 1990. Each of these patents discloses various circuitry and devices for measuring water depth through the utilization of a pressure transducer or the like. Examples of depth indicators for use by boaters and divers are disclosed in U.S. Pat. No. 2,674,881 issued to Rich on a Apr. 13, 1954 and U.S. Pat. No. 3,856,283 issued to Jennings, et al on Dec. 31, 1974.